1. Technical Field
The present invention relates to an atomic cell, an atomic cell manufacturing method, a quantum interference device, an atomic oscillator, an electronic device, and a moving object.
2. Related Art
As an oscillator having a highly accurate oscillation characteristic over a long term, an atomic oscillator that oscillates based on energy transfer of atoms of an alkaline metal such as rubidium or cesium is known.
Generally, an operation principle of the atomic oscillator is divided into a method using a double resonance phenomenon using light and microwaves, and a method using coherent population trapping (CPT) using two types of lights having different wavelengths. Any type of atomic oscillator includes an atomic cell (gas cell) in which an alkaline metal is sealed (for example, see JP-A-2009-212416).
As such an atomic cell, an atomic cell having a structure in which plural substrates are stacked, which is designed for miniaturization according to a recent demand for miniaturization of an atomic oscillator, is known as disclosed in JP-A-2009-212416. In JP-A-2009-212416, a first transparent substrate including a gas introduction portion, a second transparent substrate including a through hole, and a third transparent substrate are sequentially stacked and bonded, openings on opposite ends of the through hole in the second substrate are blocked by the first transparent substrate and the third transparent substrate to form a space, alkaline metal vapor is introduced into the space through the gas introduction portion, and then, the gas introduction portion is blocked by fusion to seal the space. Then, a stacked body formed by the first to third transparent substrates is individualized by dicing to thereby obtain an atomic cell.
In the atomic cell according to JP-A-2009-212416, since the gas introduction portion overlaps a region to be irradiated with light in the atomic cell when seen in a stacking direction of the stacked body, when light is applied from the stacking direction of the stacked body, passage of the light is interrupted by the gas introduction portion. Thus, in the atomic cell according to JP-A-2009-212416, light passes in a direction parallel to a surface of the substrate.
However, in the atomic cell according to JP-A-2009-212416, since light passes through a cut section having fine unevenness formed by dicing of the second transparent substrate, the light is scattered on the cut section, and as a result, the intensity of the light after passage is reduced.